The present invention relates to a method and system for improving or extending oil life in an internal combustion engine, and more particularly a system and method for introducing of nitrogen enriched air into a crankcase of an internal combustion engine.
In recent years, internal combustion engine makers have been faced with ever increasing customer and regulatory requirements. These requirements have been directed mainly at two aspects of engine performance, including fuel economy, reliability, maintainability and, of course emissions. Several important characteristics of engine performance are engine oil consumption and oil change interval.
Modern diesel engines have relatively large oil capacities, and it is therefore important and advantageous to decrease the engine oil consumption and also extend the useful life of engine oil during the normal operation of a diesel engine. There are numerous prior art references that suggest the engine parameters and variables that contribute to oil degradation, and attempt to monitor such parameters and variables so as to predict the engine oil consumption and oil useful life. However, there is little technology available to engine makes and customers, other than oil additives, that are effective in extending oil life or oil change intervals.
Recent advancements in diesel engine air system technologies have resulted in a technology referred to as intake air separation. Separated air (either oxygen enriched air or nitrogen enriched air) has a number of previously disclosed and beneficial uses within an internal combustion engine and a diesel engine in particular. See, for example, U.S. Pat. No. 5,649,517 (Poola et al.) which discloses the use of a semi-permeable gas membrane to remove a portion of nitrogen from the intake air flow to create an oxygen enriched air supply and a nitrogen enriched air supply and the varied uses of each. See also U.S. Pat. Nos. 5,526,641 (Sekar et al.) and 5,640,845 (Ng et al.) which disclose air separation techniques and applications for oxygen enriched air as well as nitrogen enriched air in an engine.
However, notwithstanding the disclosed uses of the nitrogen-enriched air and oxygen enriched air, further applications of this technology are still being sought. The present invention applies the air separation technology to the problem of extending oil change intervals and otherwise extending oil life.
The present invention is a method and system for extending engine oil life through the introduction of nitrogen enriched air into the crankcase of an engine or other suitable engine location. The method of extending oil life in an engine comprises the steps of separating a flow of air into a flow of oxygen enriched air and a flow of nitrogen enriched air; and directing the nitrogen enriched air into the engine at locations where lubricating oil is present. Alternatively, the method may be characterized as comprising the steps of providing a source of nitrogen enriched air and subsequently introducing the nitrogen enriched air into the engine at locations where lubricating oil is present so that the oxidation rate of the lubricating oil is reduced thereby extending oil life.
The invention may also be characterized as a system for extending oil life in an internal combustion engine. The system includes an air separating device adapted for separating a flow of air into a flow of oxygen enriched air and a flow of nitrogen enriched air. The system for extending oil life also includes a nitrogen enriched air conduit coupled to the air separation device for transporting the nitrogen enriched air into the engine at selected locations where engine oil is present.